Appointment times wrong after changing computer time
 

The timestamp on my outgoing messages were 3 hours off. I changed
the time zone on the system clock and got the correct time on my
outlook outgoing messages. However, after I "fixed" this, now all of
my outlook appointment times are off. That is, an appointment that
used to be 9:00 am is now 12:00. Is there an easy way to move all of
my appointments back 3 hours?